Breech mechanism for guns



J. T. THOMPSON.

BREECH MECHANISM FOR GUNS.

APPLICATION FILED DEC Z. 1920.

T d U U U U J. T. THGMPSON.

'BREECH MECHANISM FOR GUNS.

APPLICATION FILE DEC 2. 1920. 1,425,808, Pamfemug. 15,1922;

4V SHEETS-SHEET 2.

J. T. THOMPSON.

BREECH MECHANISM FOR GUNS.

APPLICATION FILED DEC 2.1920.

1 ,425,808. Patented Aug. 15, 1922.

4 SHEETS-SHEET 3- J. T. THOMPSON.

BHEECH MEcHANxsM FOR GUNS.

- APPLICATION FILED DEC 2,1920A 1,425,808.

4 SHEETS-SHEET 4.

Patented Aug. 15, 1922.

NNW

.m @EN @u www QM @M M mw@ JOHN TALIAFERRO THOMPSON,

0F NEWPORT, KENTUCKY, ASSIGN OR, BY DIRECT AND MESNE ASSIGNMENTS, TO AUTO-ORDNANCE CORPORATION, 0F NEW YORK, N. Y., A.

CORPORATION or NEW `YORK.

BREECH MECHANISM FOR GUNS.

Specification of Letters Patent.

Patented Aug. 15, 1922.

To all 'whom it may coi/wem.'

Be it known that l, JOHN TALIAFERRO THOMPSON, citizen of the United States of America, and resident. of Newport, in the county of Campbell and State of Kentucky, have invented new and useful improvements in Breech Mechanism for Guns, ofwhich the following is a specification.

rlhis invention relates to a breech mechanism for guns and particularly to that type which provides means for restraining the movement of thebreech closure at the time of firing and for releasing the closure after firing.

The principal objects of the invention are providing a breech mechanism which affords ,a smoothness of action during rapid fire and which permits extremely rapid lire; restraining the :breech closure by means moving in a continuing path into and out of restraining position; utilizing the movement of the breech closure in operating the restraining means; operating the restraining means on the forward or closing movement of the breech closure; and employing the restraining means for operating the liring pin. Other objects will appear from the description that follows. These objects are accomplished by a structure which may be briefly described as comprisingV a lug and mechanism for moving the lug behind an abutment on the breech closure to restrain the latter when it is in position to close the tiring chamber, and removing the lug after firing to permit rearward movement of the closure. The path which the lug follows on removal is a continuation of that which it takes on entering into contact with the abutment so that the lug always moves in the same sense or preferably in an orbit. The mechanism for securing this movement is operated by the breech closure so that it is automatlc in action and in phase with the breech closure; and in the form here adopted it utilizes the forward motion only of the breech closure to operate the restraining lug. By providing the firing pin with an end projectingI from the abutment, the lug is utilized on its entering movement for driving the firing pin to discharge the cartridge. The preferred embodiment is set forth in detail hereafter.

In the accompanying drawings,

Figure 1 is an elevation of a gun embodylng the invention;

Fig. 2 is a longitudinal section through the breech mechanism with the closure retracted;

.Figure 3 is a transverse section, on the line 3-8 of Fig. 2, through the restraining means;

Figure 4 is a section similar to Fig. 2 with the closure in forward position;

F1gure 5 is a transverse section'on the line 5*5 of Fig. 4 and similar to Fig. 3 b ut showing the means in restraining position;

Figure 6 is a longitudinal section on the line 6 6 of Fig. 4;

Figure 7 is a longitudinal section on the line 7-7 of Fig. 4;

Figure 8 is a det-ail section on line 8-8 of Fig. 2;

Figure 9 is a transverse section on the line 9 9 of Fig. 4.

Figure 10 is a transverse section on the line 10-10 of Fig. 4.

Figure l1 is a transverse section on the line ll-ll of Fig. 4; and

Figure l2 is a transverse section on the line 12-12 of Fig. 4.

The particular gun chosen for the purpose of illustration, which is of the general type shown in the U. S. Patent 1,357,208, granted Oct. 26, 1920, is provided with a fire grip 1, a rear grip 2 and a magazine 3. The receiver of this gun is made in two sections, an upper one 4 and a lower one 5, so that the gun mechanism may be assembled within it. A breech closure is mounted for sliding within the upper portion 4 of the receiver and it has a bore 7 extending Ilongitudinally of it, in which lits a firing pin 8. Also within the closure is a compression spring 9 which contacts the pin to hold it in rearward position and to project the end l0 from the bore as shown. A recoil spring 1l urges the closure into forward or closing position. On the forward end of the closure is an extractor 12 and an ejector opening 13 is provided in the receiver for the discharged cartridge.

From the rear end of the closure, an arm 14 extends downwardly and is made integral with the closure. This arm has a threaded passage through its lower end, in which is a similarly threaded shaft 15. As

y incidin shown in Fig. 2, this shaft is parallel with the direction of movement ofthe closure.

The shaft is mounted for rotation in a forward bearing 16, made as part of the receiver, and in a rear bearing 17, which is secured by a threaded connection in the receiver part 5 for assemblage purposes. The end Athrust of the shaft is transferred to these bearings by collars 18 and 19, and ball bearings between to minimize friction. The shaft extends through the forward bearing 16 into another bearing 20 also made a part of the receiver. These bearings 16`and 20 are divided on a horizontal axial plane the upper of each bearing being integral with the upper portion 4 of the receiver and the lower part of each bearing being integral with the lower portion 5 of the receiver. A

cylindrical cavity 22 is formed between the two -bearings 16 and 20, across which the` shaft 15 extends, the axis of the shaft cowith that of the cavity. j

A cy indrical block 21 lits within this cavity, l and extending through the b lock along a diameter is a chamberof rectangular cross section .in which is slidably fitted a lug 24. The lug is of a length sufficient to extend the full diameter of the block and the depth of an annular slot 26 (Figs. 3 and 5) formed in the cylindrical cavity .22. Therefore when one end lof the lugis extended intothe slot to contact with its bottom wall, the other end of the lug-:coincides with the periphery of the block as shown in Fig. 3. Both lug ends are formed to coincide with the block periphery. To permit reciprocation of the lug in the block a slot 25 is providedW for the shaft 15, extending longitudinally of the lug in the direction of its movement.

An annulus 27 projects from the forward end of the block 21 and is supported in a seat, formed to fit it, in the bearing 20.

Within this annulusis a spiral spring 28,

movement winds the spring and so tends toV Iturn the block in the same direction.

Since the lug is larger than the diameter of the block by the depth of the annular slot 26 and reciprocates in the block, either end of the lugl is projectable the full depth of the slot to bring the other end within the block periphery. One of these lug ends is provided on the forward side with a earn face, 35 and the other end is similarly provided with a cam face 35. These cam-faces are arranged for cooperation with a similarly inclined cam face 34 of an abutment formed by a slot 33 provided in the closure. The axis of the cylindrical block 21, as it coincides with that of the shaft, is parallel to the direction of movement of the closure and the block is so positioned relative to the closure that the bottom surface of the closure clearsthe periphery of the block. The vclosure movement therefore is across the annular slot 26 which is concentric with the block and formed in the wall of the cavity'22 in which the block is seated. Rotation then of the block with an end of the lug projecting into the slot, brings this projecting end into the path of the `closure for restraining the closure as-shown' in Figs. 4 and 5. Radial movement of the lug removes it from the path of the closure and projects the opposite end of the lug into the` annular slot, as shown in Figs. 2 and 3. This end can then be rotated into the path of the closure. ranged to hold the closure in each of two positions of the lug, the opposite ends of the lug alternately moving into restraining po Consequently the lug is ar sition while the lug rotates 180o between the restraining positions. Viewed from the rear of the gun, the lug rotates each time in a clockwise direction, each end of the lug having' the same direction of rotation. y The cam face 34 of the abutment on the closure is that with which the lug through its cam face 35 or 35 contacts to restrain movement of the closure at the time of iring. The angle at which these cam faces are formed is preferably made in accordance with the principle explained in 'the patent to Blish 1,131,519, March '9, 1915. When so formed, the restrainingr lug holds the clo-A sure until thepressure has dropped to a safe value, and then the closure drives the lug out of its path bymeans of the cam action.

. As a means of insuring alignment of the lug with the closure so as to be in restraining position, the annular slot 26 is not made continuous but is terminated by a wall 61 on one side of the receiver as shown in Figs. 3 and 5. The slot then extends on the other side only of the receiver providing' for a 180o rotation of the lug.

' The lug 24 is substantially twice as wide as the closure and the radial walls of the annular slot 26 provide shoulders 60 Fig. 6'on each side of the closure against which the lug abuts when in restraining position. By this construction the breech pressure is trans, mitted by the closurethrough the lug to the receiver,l the extent of surface contact hef tween the lug and receiver being practically he same as that between the closure and the ug. l

As the vtiring pin has an end 1() projecting from the cam face 34, this end lies in the path of the lug when it rotates into restrain- L rotating block 21,. The entering end of this groove is deep enough to ride over the firing pin as the lug rotates; but the bottom 37 of the groove is inclined toward the surface of the cam face so that the pin is driven entirely into the closure as the lug continues its rotation into restraining position. The

pin being then within the closure, the lug is tree to be moved out of its restraining position.

To insure the projection of the lug from the block as the end of the lug is rotated in the slot 26 into restraining position, catches are provided consisting of balls 38 in the block 21 urged by springs 39 into seats in the lug. These catches yield when pressure is exerted on the lug sliding it in the block.

As the block is rotated by means of its spring connection with the shaft, a lock is preferably provided to hold the block from rotation until sufficient energy is stored up in the spring to rotate the block, and the lug carried by it, withv sutlicient torce to operate the firing pina This loclv. consists ot a spring pressed plunger 49 carried in a recess of the block and another spring pressed plunger 4l carried in. a recess in the bearing 16. When the lug is in alignment with the closure these recesses are also in alignment. The pressure of the spring in the plunger 40 is sutliciently greater than that ot the spring associated with the plunger 41 so that the plunger 40 enters the recess or the plunger 41 and so locks the block against rota-tion. The plunger 41 has an end extending through the bearing and projecting beyond it and this projecting end is contacted by a surface 43 provided on the closure when the closure is near the end of its forward movement. Pressure on the end 42 causes the plunger 4() to recede in its recess so that the bloclr 1s free to v turn. A. duplicate recess and plunger 40 is provided in the block for engagement when the block has made a halt rotation presenting the other end ot the lug for restraining the closure.

The arm 14 extending trom the closure for engagement with the shaft has notches 45 on its lower surface. A sear 46 is provided to engage these notches to hold the closure in a retracted position. A. trigger 47 operates the sear through a disconnector 48 tor releasing the closure. This Sear ismade in two parts 49 and 50, as shown in Fig. 12, and the disconnector engages only the part 49. Both parts are mounted on the same pivot pin and heid from movement relative to each other by a spring pressed plunger 51 carried by the part 49 fitting into a recess in the part 50. This plunger has an extension passing through the part 49 beyond its outer side and on this extension is a depending cam portion 53. Pivoted in the receiver below this portion of the sear is a cam 52. lVhen this cam 52 is upturned and the end of the sear carrying the cam is depressed by the trigger, the cam is in position to engage the portion 53. This engagement causes the portion 53 to move from the other portion of sear and draws the plunger 5l with it out of the Sear part 50. As each part 49 and 50 has its own spring 49 and 50 to force trigger only engages the part 49, the part 50, as soon as released, moves upwardly in position to catch the closure notch when the closure retracts. Therefore continued pull on the trigger does not release the closure more than once, when the cam 52 is in upturned position. lith this position then the gun acts as a semi-automatic gun tiring only once for each time that the trigger is pulled. Release ot' the trigger permits the part 49 to move upward and the plunger 51 again secures the two parts 49 and 50 together.

For preventing all movement of the sear and consequent release of the bolt another cam 54 is provided in the same mounting as the cam 52 but extending in the radially opposite direction. This cam when upturned engages both lower surfaces of the sear parts 49 and 50 and holds them from any movement. The mounting provided with these cams 52 and 54 has a handle 57 on the exterior' ot the receiver. Indicating marks (Fig. l) on the receiver show the proper position ot the handle for turning cam 52 for coaction. in which case the gun is semiautomatic; or for turning cam 54 into contact, or sate position; or for turning both cams out ot coaction, for full automatic gun fire.

Un the forward end of the receiver is an arm 55 ixedly connected to the trigger. This arm lies in the path of a projection 56 formed on the magazine follower. Contact of this projection 5G with the arm 55 throws the trigger forward, permitting the scar to be sprung into position to engage the closure, when the latter returns to its retracted position. Thus the breech closure is automatically caught in retracted position when the magazine becomes empty.

ln assembly, the mechanism, the closure 6, with the shaft l5 and block 21 attached to it is placed in the portion 4 of the receiver. in proper relation to the upper parts of the bearings 16 and 20, the bolt being in the retracted position. The bolt is then moved forward and the recoil spring inserted. The part 5 of the receiver with the trigger mechanism assembled in it is next secured to the part 4. The end bearing 17 for the shattis then fitted on the shaft and screwed into its seat in the part 5 of the receiver.

In operation the closure 6 being in retracted position is released from the Sear.

nthe closure engaging end upward, and the The forward motion of the closure rotates the block, Y,to which the spring is secured remains stationary. When the closure reaches its forward position, the face 43 contacts with the projecting end 42 of the plunger 41 and so releases' the block 21. The spring 28 then rotates the lug 24 through the block into the slot 33 of the closure 6. The cam groove 37 in the lug (Fig. 6) advances the firing pin as the lug moves into position behind the abutment 311,A so that the gun is fired as the lug reaches its restraining position. closure pressing on the cam face 35 of the lug forces the lug to slide in the chamber 23 from the position shown in Figs. 4 and 5 to the position shown in Fig. 3. The closure is then free to recoil, and this operation con tinues as long as the closure is released.

An important feature of the invention lies in the double breech-closure restraining lug each end of which serves in turn as a lock for the closure, one end moving toward locking position as the other end moves out lof locking position when the gun is in op,-

eration. Another important feature of the invention is in the restraining means moving in the same angular direction into and out of restraining position. Thus in the illustrated embodiment the restraining means rotates in a clockwise direction (viewed from the rear) into restraining position and likewise in a clockwise direction out of restraining position.

1 claim:

1. A gun having in combination: a firing chamber, a breech closure movable i-nto and out of position for closing the firing chamber, a member for restraining the closure, and means actuated by said breech closure Jfor moving "the member in a continuing path first into restraining position and then out of restraining position.

2. A gun havingin combination: a firing chamber, a breech closure movable into and out of position for closin the firing chamber, a member for restralnin the closure, and means actuated` by said reech closure for moving the member in an orbital path first into restraining position and 'then out of restraining position. f

3. A gun having in combination: a firing chambera breech closure movable into and out of position for closingthe firing chamber, a member for restraining the closure, means for moving the member in a continuing path first into restraining position and then out of restraining position, and means for operating the first named means by the breech closure.

4. A gun having in combination: a firing After firing, the cam face 34 of' the,

chamber, a breech closure movable into and out of position for closing the firing chamber, a member for restraining the closure, means for moving the member in an angular directioninto restraining position, and means for moving the member in the same angular direction out of restraining position, one of said means being actuated by said breech closure.

5. A gun having in combination: a firing chamber, a breech closure movable into and out of position for closing the firing chamber, a member for restraining the closure,

moving the member out of restraining position along a continuation of said path, said last named means being actuated by said breech closure.

6. A gun having in combination a firing chamber, a breech closure movable into and out of position for closing the firing chamber, a member for restraining the closure, means for moving the member along a path into restraining position and separate means operable by the breech closure for moving the member out of restraining position along a continuation of said path.

7. A gun having in combination: a firing chamber, a breech closure movable into and out of position for closing the firing chammeans for moving the member along a path into restrainingv positlon, and means for 8. A gun having in combination: a firing 'y chamber, a breech closure movable into and olilt of position for closing the firing chamber, a member for restraining the closure, means for moving the member in a continuous path, firstinto and then out of restraining position, and a lost motion connection between said means and the closure.

9. A gun'having in combination: a firing chamber, a breech closure movable into and out of position for closing the firing chamber, a member for restraining the closure,

means for moving the member in a continuous path, first into and then out of restraining position, and a spring connection between said means and the closure.

10. A Agun having in combination: a firing chamber, 'a breech closure movable into and out of position for closing the firing chamber, a member for restraining the closure, means for moving the member in a continuous path, first into and then out of restraining position, a lost-motion connection between said means and the closure, and means to retard the member until the closure is in cooperating position therewith.

11. A gun having in combination: a firing chamber, a breech closure movable into and ing chamber, a

out of position for closing the 'tiring chamber,'a member for restraining the closure, means for moving themember in a continuous path, first into and then out of restraining position, a spring connection between said means and the closure, and means to retard the member until the closure is in cooperating position therewith.

12. A gun having in combination a iring chamber, a breech closure movable into and out of position for closing the firing chamber, a member for restraining the closure, means for moving the member in a path into restraining position, an abutment for aligning the member in such position, and means for moving the member in a continuation of said path out ot restraining position.

13. A gun having in combination: a irin@f chamber, a breech closure movable into and out ot position for closing the tiring chamber, a member for restraining the closure, means for moving the member in a path into restraining position, an abutment for aligning -the member in such position and separate means for moving the member iii a continuation ot said path out of restraining position.

1lie. gun having in combination: a tirreceiver, a breech closure movable in the receiver into and out oi posi- 'tion to close the bring chamber, member for restraining the closure rotatably mounted in the receiver, means to rota te said meniber in a path. into restraining position, an

' abutment tor aliwuinir said member in such its position, and means tor moving said inember in a continuation of said path out of restraining position 15. ifi gun having in combination: a firing chamber, a receiver, a breech closure movable in the receiver into and out oit position to close the tiring chamber, a member for restraining the ciosure slidabiy mounted in the receiver, means to move said meinbcr in a path into restraining position, an abutment for aligning said einber in such position, and means for slid-ably moving said member in a continuation ot said path out of restraining position.

16. A gun having in combination: a tiring chamber, a receiver, a. breech closure movable in the receiver into and out of position to close the tiring chamber, a member for restraining the closure rotatably and slidably mounted inthe receiver, means to.

rotate the member in a path into restrain- Aing position, an abutment for aligning the member in such position, and means for slidably moving the member ina continuation of said path out of restraining position.

173A gun having in combination: a-

breech closure movable into and out of firing position, an abutment thereon and means for restraining the closure in firing position,

said means comprisin a member rotatably mounted on a shaft su stantially parallel to the axis of the closure and a lug movably mounted on the member to move behind the abutment.

18. A gun having in combination: a breech closure having an abutment movable into and out of firing position and means for restraining the closure in firing position, said means comprising a member rota.- tably mounted on a shaft substantiallyY parallel to the axis of the closure and a lug movably mounted on the member to move behind the abutment, said lug and abutment having engaging surfaces inclined to the path of the closui'e at suoli an angle that the `lug is automatically forced out of the path of the closure by the breech pressure acting through the closure after the breech pressure has decreased to a safe value.

19. A gun having in combination: a firing chamber, a receiver, abreech closure movable in the receiver into and out of position to close the firing chamber. a member for restraining the closure rotatably mounted in the receiver, a lug slidably mounted in the member, means to rotate the member to bring the lug into rest-raining position, and means tor slidably moving the lue in the member for removing said lug from restraining position.

20. A gun having in combination: a tiring chamber, a receiver, a breech closure movable in the receiver into and out of position to close the firing chamber, a member for restraining the closure rotatably mounted in said' receiver, a lug slidably mounted in said member, means to rotate said member to bringthe lug into restraining position, an abutment for aligning the Hlug in such position, and means for slidably moving the lug in said member out of restrainingy position.

21. A gun comprising in combination: a firing chamber, a breech closure movable into and out of po-sition for closing the tiring chamber, a membei having a plurality of surfaces for contactingand restraining the closure, and means for moving the member and successively bringing said surfaces into and then out of restraining position.

22. A. gun comprising in combination: a. tiring chamber, a breech closure movable into and out of position for closing the tiring chamber, a member having aplurality of surfaces for contacting and restraining the closure, and means for mov- `in the member with two ends, either end being projectable from the member, means for moving the member to bring a projecting lug end into( position for restraining the closure, and means for moving the projecting lug end out of restraining position and simultaneously projecting the other end from` the member. j

24. A gun having in combination: a {iringchamber, a receiver, a breech closure movable in the receiver into and out of position to close the firing chamber, means for restraining the closure, an arm extending from the closure, and a shaft threaded in the'arm and mounted for rotationin the receiver, said shaft on-rotation `storing up energyAto operate the restraining means.

25. ing chamber, a receiver, a`breech closure movable in the receiver into and out of position to close the iiring chamber, means for restraining the closure, an operating means mounted in the receiver for movement in op osite directions, and a ratchet connection tween the restraining-` means and operating means, whereby the restraining means operates on movement in one direction only of the operating means.

26. A gun havingtin combination: a firing chamber, a receiver, a breech closure movable in the receiver into and out of position to close the firing chamber, means for restraining the closure, an operating means mounted insaid receiver for movem-ent in opposite directions, a ratchet con-- nection between thev restraining means and voperating means, whereby the restraining means operates on movement in one direction onlyof the operating means, and a lost motion connection between the ratchet connection and operating means.

27. A gun having in combination: a fir- Y ing chamber, a receiver, a breech closure movable in the receiver into andout of position to close the firing chamber, means for'restraining the closure, an operating means operated by the closure mounted in said receiver for rotation in opposite directions, and a ratchet c`onnection between the restraining means and the operating means, whereby the restraining means operates on rotation in one direction only of the operating means. y Y p 28. A gun having in combination: a firing chamber, a receiver, a ibreech closure movable in the receiver into and out of position to close the firing chamber,`means for restraining the- 'closure, an operating means operated .by the closure and mounted in said receiver for rotation in opposite directions, a ratchet connection between the restrainingvmeans and operating means,

whereby Cthe restraining means operates on rotation 1n one direction only of the' operating means, and a lost motion connectlon begun having in combination: a ir-A tween said ratchet connection and operating means. g

29. A breech mechanism for an automatic gun, consisting of a breech closure, a iring pin in the closure and having a projecting endrestraining means for said' closure comprising a member movable into the path of the closure for contacting the end to operate the-pin, and a lost motion means connecting the closure and restraining means for moving the member.

30. A breech mechanism for an auto-- matic gun, consistingv of a breech closure, a firing pin in the closure and having a projecting end, restraining means for said closure comprising a member movable into the path of the closure for contacting the end.'

-retard said member until the pin is inncooperating position therewith.y

31. A breech mechanism for an automatic gun, consisting of a breech closure, a firing pin in the closure and having a projecting end, restraining means for aid closure comprising a member movabls into the path of the closure for contacting the end to operate the pin, and spring means connecting the closure and restraining means for movin the member.

v 32. breech mechanism for an automatic gun, consisting of a breech closure, a firing pin in the closure and having a projecting end, restraining means for said closure comprising a member movable into the path of the closure for contacting said end land operating the pin, spring means connecting said closure land restraining means for moving said member, and a means to retard the member until the pin is in cooperating position therewith.

' 33. A breech mechanism for an automatic gun, consisting of a breech closure, a firing pin in said closure and having a projecting end, a member movable into the path of the closure for contacting'said end to operate the pin, means connecting said closure and member for moving said member, a means to retard said member until Athe pin is in cooperating position therewith,

and means on said closure for releasing said retarding means.

34. A gun having a movable breech closure, an abutment thereon, and means for restraining the closure in tiring position comprising a rotatable member, means for rotating said. member in a continuous path in one direction, and a lug movably mounted on the member to move behind the abutment. i

35. A gun comprising a/b'reech closure movableto and fro automatically in response to the breech pressure, a lock movable along an endless'path intersecting the path of the breech closure, the closure and lock having abutments adapted to engage each other as the lock closes the path of the closure' to restrain the closure in firing position, and means responsive to said lock for firing the gun as the lock crosses the path of the closure.

36. A gun comprising a breech closure movable to and fro automatically in response to the breech pressure7 alock rotatable transversely to intersect the path of the breech closure, the closure and lock having abutments adapted to engage each other as the lock crosses the path of the closure to restrain the closure in firing position, and means responsive to said lock for firing the gun as the lock crosses the path of the closure.

Signed by me at New Canaan, Connecticut, this 30th day of November, 1920.

JOHN TALIAFERRO THoMPsoN. 

